The purpose of this is study is to identify how customer’s perception of customer complaint service is by applying the theory of the service quality Zeithaml including reliability, responsiveness, assurance, empathy, and physical evidence. By analyzing the extent of the customer's perception of service quality complaints in the Regional Water Company Pekalongan. The final task is written using descriptive analysis method. In this study purposive sampling is used. Data were collected by observation, literature and questionnaires. The population of this research is the users or customers of “PDAM” Pekalongan, who still have active connections, to determine the sample size using the formula of Slovin. The conclusion is of 5 dimensions of service quality that is used as a basis for assessing the quality of service of existing customers, tangible dimension assesses the performance has been good because it has the highest score by an average of 3.20, while for the lowest score by an average of 3 on the dimension reliabillity. Constraints faced by the existence of delays and mismatches of input data. It is suggested the existence of training on inputting data with the online system is maintained in order not to hinder the quality of the company's performance.